I installed the Really Simple Series plugin to try to automate the task of adding a list of other posts in a series to the end of every entry in that series. The plugin allows me to tag a category as a series and then appends an unordered list of series entries at the end of each post.

Two issues:

1. I need the plugin to display the meta data for the post instead of the post title.
2. I need the plugin to display the list even in the main blog loop and category listing, and not just the individual posts.

Here's the code for the plugin:

<?php
/*
Plugin Name: Really Simple Series
Plugin URI: http://krogsgard.com/2012/simple-wordpress-series-plugin
Description: This plugin changes the default order of selected categories used to ascending (oldest first). It also lists all posts in the selected categories at the bottom of each post in the series.
Version: 0.1
Author: Brian Krogsgard & Pippin Williamson
Author URI: http://krogsgard.com
Contributors: krogsgard, mordauk
Thanks: Tom McFarlin, and Ryan Imel for your help, even though you don't know it : )
License: GPLv2 or later
License URI: http://www.gnu.org/licenses/gpl-2.0.html
*/

class RSSeries {

// static property to hold singleton instance

static $instance = false;

// this is the constructor, which is private to force the use of
// getInstance() to make this a singleton

// $category = get_query_var('cat'); doesn't work, so i used used get_term_by and get_query_var( 'category_name' ) instead to reverse retrieve the ID
// it must be a bug with pre_get_posts as I ran into the same thing recently too https://gist.github.com/bb26c6074c358389a039

// function to add the list of posts in the series on the singular view only when that post has our category defined
// thanks Pippin Williamson @ pippinsplugins.com for making sure I filter the content properly